where tamerlan goes for six months. he flies to moscow. but then, according to his father, he visits chechnya and dagestan. now, who did he visit in chechnya? who did he visit in dagestan? does it have any relationship to these unspecified underground groups that the russians referred to in their original request to the fbi? third, you come back to the united states. by this point he clearly seems to be thoroughly radicalized. he sets up that youtube account filled with jihadjihadi videos. we have reports from radical tendencies even from people within his own mosque. who was he in contact with in the boston area? i think those are the biggest questions now facing investigators and people looking at how the fbi handled this case. >> michael isikoff, i got to leave it there. you're right. we got to figure out did the kgb not tell our guys or russian intelligence not tell our guys everything that they knew at the time? and will they tell us now? anyway, michael, thank you very much. >>> gaggle will be here next. running a little bit late. fi